<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			var a = prompt("请输入几行");
			var c = a ;
			for( var i = 0 ; i <= a ; i++){
				for( var b = 0 ; b < c ; b++){
					document.write("*");
				}
				document.write("<br/>");
				c--;
			}
		</script>
	</head>
	<body>
	</body>
</html>
